JP3222590B2 - Apparatus and method for manufacturing glass pressed product - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention mainly relates to a method for melting glass material or vitrified cullet, such as an optical lens, flowing out clarified molten glass, cutting it into an appropriate amount of gob, and pressing it. The present invention relates to the structure of a production line for obtaining lens blanks before grinding and polishing.

[0002]

2. Description of the Related Art Generally, there are generally three methods for obtaining lens blanks. (1) One method that has been practiced since ancient times and is still in operation is called a hand press. In this method, a sheet of glass is cut and trimmed, and the glass lump relatively uniformly rubbed by a barrel polishing method is heated in a simple furnace, softened, and then placed in a predetermined mold. Insert
This is a method in which pressing is performed by pressing an upper mold and a lower mold by a press method using a hand mechanism or an actuator method. (2) As a next method, the glass directly flowing out of the melting tank is used as a gob (generally, a glass lump before molding) to form a lump of raw material for each unit, which is then indexed ( (In general, 6 to 12 indices) Directly insert or put into a mold arranged in a circular table shape,
A method of continuously pressing while sequentially indexing by a press mechanism provided at one place of this rotary table is called a direct press method, so-called DP. (3) Furthermore, as the multiple simultaneous press method of (1),
Either a lump of glass that can be used for a so-called hand press uniformly roughened or a gob made by directly pulling up from a melting tank made during DP, but this is also made of refractory material. This is a method of manufacturing lens blanks obtained by placing the pieces on a dish and simultaneously reheating a plurality of pieces in a high-temperature heating furnace to soften the pieces, then taking out the pieces and pressing the pieces at the same time.

[0003]

However, the conventional production systems described above have advantages and disadvantages, respectively.
In recent years, it has not been possible to satisfy the modern demands of "high-mix, low-volume production", "high efficiency, low cost", "high quality, high added value". These market demands have been viewed as extremely difficult issues because, in the conventional scheme, conflicting demands must be met simultaneously by one method. That is, in the hand press method (1), it is extremely difficult and takes a long time to obtain a uniform polished glass lump before pressing at a high yield without any damage. Furthermore, there is a large variation in quality, the need for human labor is high, and the productivity is increased.

[0004] The DP method (2) is a method which is widely used by major companies as the most advanced method in recent years, but it is a method which is certainly effective while the market demands mass production. there were. The gob is made directly from the melting tank and pressed continuously, so there is no waste in production, the amount of energy per product is the least, and it is easy to be automated, so less manpower is required, as long as the yield is improved. It was a very powerful method. However, as the demand for high-mix, low-volume production increases in recent years, setup changes, model changes,
At present, when the frequency of replacing machines has increased, the actual production time, which is the effective production time, has decreased, and the economic merit has been gradually reduced. Furthermore, in this type of machine, the time to make the gob and the time to press are linked to each other and are constrained, so that the press time and the related time before and after the press are lengthened to obtain a press product with higher precision in shape, Reducing the viscosity of the molten glass and increasing the speed at which the glass is pulled up to obtain a pressed product with high efficiency is a practical drawback at the production site in that a contradictory inconsistency occurs in maintaining and improving the shape and accuracy.

It is known that when a glass is pressed, a temperature gradient of a gob having a low inside and a high outside has higher press forming accuracy. Therefore, the method of (3) is (1),
This method was developed as a method that complements the disadvantages by taking advantage of the advantages of the method (2). However, it requires a large number of refractory dishes, leaves a problem with the release agent, and drops and inserts. There are drawbacks such as that the gob is not uniformly placed in the center of the mold, the shape quality is not stable, high yield is difficult to guarantee, and the volume range that can be pressed simultaneously with different types of molds is narrow,
It cannot meet the demands of the current market. As described above, it is difficult for the conventional methods to simultaneously satisfy the many demands of the market, such as “high-mix, low-volume production”, “high efficiency, low cost”, and “high quality, high added value” with a series of machinery. Was.

[0006]

SUMMARY OF THE INVENTION The present invention solves the first problem of "multi-product, small-quantity production" by separately arranging a single heating furnace and a press machine in parallel. The saucer and press mold can be changed.
Therefore, since heating and pressing conditions can be selected according to the shape, size and importance of each gob and lens, not only can the pressing accuracy be improved, but also various types of lenses can be simultaneously and continuously heated and pressed one after another. can do. on the other hand,
The gob machine is also provided with a plurality of gob dies (FIG. 1 shows an example of an 8 index). The gob dies are arbitrarily selected according to the size and shape of the pressed product. It is possible to correctly correspond to the die of the press machine.

[0007] As can be seen from the figure, different types of gobs are successively supplied from a gob machine one after another, supplied from a first conveyor to each heating furnace and a press machine by a program, and are independently pressed independently. It is in a state where it is being driven. Although the present invention has been devised for multi-kind production, simultaneous mass production is possible by using the same gob mold and the same press mold depending on the situation. Further, it is preferable that the number of stations of the gob machine and the number of press machines are the same, and it is preferable that the programming is easy and the number of mistakes is small.
Further, in FIG. 1, the form of the gob machine is a rotary table with a rotary table, but the present invention is not necessarily limited to this form, and the hot gob is directly made by other means. Any device having the function of forming a gob may be used.

[0008] Regarding the second problem of "high efficiency and low cost", the molten glass in the tank is heated to a higher temperature than before.
It is possible to achieve high efficiency and low cost by increasing the gob forming speed by raising the viscosity to the limit where the machine can be operated with low viscosity and by reheating the gob. In addition, compared to the conventional apparatus, the number of dies for pressing can be selected to be the minimum number, and the time for exchanging dies can be simplified because only one set of dies is used for one press machine. In addition, it is possible to prevent a decrease in productivity such as stopping all the devices when changing the mold. Furthermore, since the number of molds is small, the mold material can be inexpensive, and the short delivery time can be achieved by the parallel production of the different types. As described above, the present invention is an apparatus having means for solving the second problem of “high efficiency and low cost”.

[0009] Regarding the third problem, "high quality, high added value", the system can make the state of the thermal gradient of the gob be in the state of low inside and high outside. Also, the press and the time before and after the press may be completed until the next gob comes (before the gob supplied at the eighth index in the case of an 8-index gob machine), The time required can be selected in a state where there is ample room. Therefore, the selection of the pressing conditions can be made extremely high in degree of freedom, so that a highly accurate pressed product can be obtained. Further, the cutting allowance in the polishing process is reduced by half
It can be reduced to about 1/10. Therefore, it is possible to increase the added value and supply it to the market.

[0010]

The molten glass that has flowed out of the melting tank through the outflow pipe flows out to a gob mold provided in a gob machine, and is cut by a shearing device (not shown) at an appropriate time (weight and volume are controlled). (In the case of low-viscosity glass, there is also a method that utilizes surface tension.) The gob machine is sequentially rotated by the index of the table, and while the upper surface is naturally formed, the entire gob is naturally cooled and solidifies from the surface layer (during this time, It may be cooled or heated depending on the degree of solidification). After reaching the appropriate hardness, it is transferred from above, below, left and right to a heat-insulated and warmed conveyor by a slide pad on the transfer guide. When the transferred gob comes in front of a predetermined extruding mechanism while maintaining an appropriate temperature state, the gob is transferred to the gob receiving tray by a V-shaped pusher provided at the tip thereof in accordance with a previously set program.

The gob receiving tray and the receiving tray supporting rod that have received the gob can be moved forward, backward, left and right in a horizontal plane by an XY stage. The gob receiving tray that received the gob is inserted up to the center of the heating furnace that has been heated and held at a predetermined temperature in advance with the lid opened, the heating furnace lid is closed in a state where it is in a fixed position, and the press suitable temperature above the softening point of the gob Enhance. When the temperature of the press reaches an appropriate temperature, the lid of the heating furnace is opened, and the gob moves again to the gob transfer position with the rotating arm together with the gob receiving tray by the action of the XY stage. Transferred to the lower mold) and inserted.
During this process, only the lower portion may be heated in the suction state in order to avoid lowering the temperature of the bottom of the gob.

The gob that has entered the mold (lower mold) of the press machine is pressed and molded by the molds (upper mold and lower mold) set to a predetermined press pressure. The pressed and molded glass is turned into a lens shape, pushed up by an arrow shaped attached to the inside of the lower mold, and sucked up again by the rotary suction pad,
The wafer is rotated, transferred to the second conveyor, and transported to the next annealing step. It should be noted that the XY stage, the shearing, the suction pad, and the like shown here are not limited to the system shown in the drawing since any other device that performs the same operation can be considered.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a plan view showing the overall configuration of a production line showing the flow of works (the gob W and the pressed product P) and the arrangement of each device in the present system. That is, in this system, the work flows from the top to the bottom of the drawing, and the glass melted in the upper melting tank 1 is poured into the gob machine 3 to form an appropriate amount of gob W.
It is transferred to the first conveyor 7. Since the first conveyor operates continuously and continuously (in some cases, intermittent feeding is also possible) so as to convey the workpiece downward in the drawing,
Gob W follows A, B, C, D, E,
It is carried to the position of each station of F, G, H. The gob W arriving at each station is transferred to the gob receiving trays 11 _{-1 to} 11 _-8 and then inserted into the heating furnace 8 which has been heated in advance and heated.

The heated gob W is further rotated by a rotary arm 14.
Is transferred to the press die 15 of the press machine 9 and pressed to be a pressed product P, which is replaced by the second conveyor 31 by the same rotary arm 14.
Like the first conveyor 7, the second conveyor 31 is always operated continuously so as to carry the work downward in the figure, so that the second conveyor 31 flows downward. Although not shown in this figure, there is an annealing step below the figure,
The method of collecting and distributing the pressed products P is different between the case where the annealing step is performed continuously and the case where the annealing step is performed by the batch method. These arrangements can be changed at any time according to the layout and space of the factory, and FIG. 1 merely happens to be a vertically long arrangement.

More specifically, the melting tank 1 is generally installed at a predetermined height, and the surroundings are heated from the bottom thereof.
The molten glass flows out through the heated outflow pipe 2 at a preset temperature at an optimum viscosity suitable for processing. A gob machine 3 generally provided with a plurality of gob molds 4 on a circular table is installed at the end of the outflow pipe. When the glass reaches a predetermined amount, the gob machine 3 is cut by a sharing device (not shown). You. As mentioned above,
Although the figure of the gob machine is of a rotary table type, it may be of an XY table type, a fan type or other types. Further, the glass is cut to reach a predetermined amount, and the control of whether or not the glass has reached the predetermined amount is generally preferably controlled by time. However, feedback control by weighing or other methods may be used. The cutting method may be any of a cutting method using a blade and a cutting method using surface tension.

In the rotary table system of the gob machine, the gob die 4 rotates sequentially while indexing one by one every time a predetermined amount of gob is formed. The figure shows a state in which it rotates clockwise. A slide pad 6 for holding the gob by suction at one end of the gob machine 3 is provided on the transfer guide 5 and serves to suck and hold the gob on a plane and transfer it to another place. In the figure, it moves from top to bottom. Of course, other methods such as an extrusion method and a drawer method may be used for this transfer. The method having the highest stability may be selected in view of the type and viscosity of the glass to be manufactured, the shape of the gob, and the like.

The gob needs to be cooled appropriately in order to solidify the skin from the outflow point of the glass to the suction pad, so that the gob is prevented from being deformed. Therefore, it is desirable that the outflow point of the glass and the suction point of the gob by the suction pad be separated from each other by several stations on the circular table. Also, if it is cooled too much, the heat retention and heating time in the next step,
Since a problem may occur due to a delicate relationship with the heating temperature, a heating device using a burner may be attached during this time. Near the other end of the transfer guide 5, the first conveyor 7 is positioned such that one end of the conveyor belt comes to a position suitable for transferring the gob by the slide pad 6.
, And the gob W moves on this conveyor on a belt toward the lower side of the figure. Since the first conveyor needs to maintain an appropriate high temperature state (upper limit of annealing temperature), it is necessary to surround the periphery in a tunnel shape, heat the inside with gas or electricity, and use a heat-resistant material for the conveyor belt. is there.

After reaching the predetermined positions A to H, the gob W is pushed out from the position substantially at the center of the belt width by the pushing mechanism 10 in the waiting direction of the gob tray 11, so that the gob W The windows are opened in advance at the respective required positions of A to H, or are opened and closed as necessary. The extruding mechanism 10 is composed of 10 _-1a to 10 _-8a , and is _disposed in parallel with the upper surface of the first conveyor 7 and at a position close to the contact position as if almost in contact with the belt so as to operate at right angles to the movement of the belt. It is located at each operating position. If necessary, the first conveyor 7 can easily allow the gob to enter the gob tray by intermittent movement.

At each of the operating positions A to H, a press unit including a material handling apparatus, a heating furnace, and a press shown in FIG. 4 is provided in parallel with the direction in which the glass moves from right to left and at right angles to the first conveyor. They are arranged in parallel. The press unit shown in FIG. 4 may be of the same shape and the same size or the same shape and the different size depending on the shape of the pressed product.
Any type can be selected as long as the size of the gob can be balanced with the delivery of the gob W and the pressed product P without any trouble.

Next, the heating furnace shown in FIG.
Will be described. The heating furnace 8 requires a slight heating up to the pressing temperature because the gob W before reaching the heating furnace is heated to a temperature close to the annealing upper limit temperature and passes through the tunnel type first conveyor 7 kept warm. In particular, the temperature may be increased with emphasis on the gob surface temperature. The heating furnace shown in FIG. 8 is one example. The furnace body 17 and the heating furnace cover 18, post 24 _-1, the actuator 19, the furnace cover consists guide bar 24 _-2 18 actuator 19, supported by struts 24 _-1
As a result, it is opened and closed up and down using the guide bar _24-2 as a guide.

An opening 20 is provided in a part of the heating furnace main body 17 so as not to hinder the insertion and removal of the gob tray, and the inside of the outer wall is entirely covered with the heat insulating material 2 except for the upper surface and the opening 20.
2, a heating element is provided inside to prevent heat radiation to the outside. The heating furnace cover 18 is provided with a groove 21 through which only the tray support rod 13 can pass, a heat insulating material 23 is disposed on the entire inner surface except for the groove and the lower surface, and a heating element is provided on the inner upper surface. When heating the gob W transferred to the gob tray,
First, a signal indicating that gob W has been transferred to the gob tray,
The heating furnace cover 18 is raised by the action of the actuator 19 using the guide bar 24 as a guide, and
Opening 20 is sufficiently opened. Next, the gob tray 11 supported by the tray support rod 13 is moved to the lid X holding the gob W.
The furnace enters the furnace by the action of the Y stage 12. Next, the heating furnace cover 18 descends, leaving the gap between the groove 21 of the cover and the tray support rod 13 and the gap between the cover and the body in a closed state, and reaches a predetermined high temperature in a short time. After reaching the high temperature, the gob takes out the gob W together with the gob tray out of the furnace by a reverse procedure of the heating procedure.

In the press machine shown in FIG. 3, a pair of upper and lower press dies (generally, the lower mold 26 is composed of a body mold _26-1 and an arrow mold _26-2 ) are arranged on the press machine body 30 as shown in the figure. Then, an upper die is pressed by an actuator or an arrow is pressed upward to produce a pressed product. In particular, in the case of producing a high-precision pressed product, a subtle change in the position of the arrow may be required. In this case, a servo mechanism 29 is provided to control the upper and lower positions.

FIG. 4 is a plan view showing an example of an arrangement of a material handling device, a heating furnace, and a press unit including a press machine. The figure shows the XY stage 12 and the rotary arm 14 on the upper surface of the frame 34 of the material handling device.
In addition, a heating furnace 8 and a press 9 are mounted on the side of the heating furnace 8 in order to ensure the accuracy of the relative positions. X
The Y stage moves the X slide and the Y slide individually or in combination in the XY directions in order to move the pan support rod 13 supporting the gob pan 11 to a predetermined position.

The state of S indicates that the gob tray 11 waits until the gob is received by the tray, R indicates a state where the gob is inserted into the heating furnace, and Q indicates the state of S after the gob is heated. Returning, the Y slide 33 moves downward in the figure, and the X slide advances to the left in the figure to advance the gob tray 11 with the gob W to the transfer position with the rotary arm, and the rotary arm is also in that position. This shows the state that has been reached. The above series of movements is controlled by a pre-set program, the gob W is heated to a predetermined optimum temperature, and after performing the optimum pressing according to a predetermined process and time, the pressed product is again rotated by the rotary arm 14. It is transferred from the press die 15 to the second conveyor 31.

[0025]

Therefore, according to the present invention, the gob created by the control of the predetermined gob mold, the outflow time and the shearing device by the gob machine is transferred to the tunnel type holding conveyor and then transferred to the gob receiving tray. After being inserted into a heating furnace and heated, the gob is delivered to a transfer location with the rotary arm, and then inserted into a press to be pressed to form a pressed product. On the other hand, the gob tray returns to the original gob transfer place. The next gob is supplied to the gob tray every cycle during this period. In the figure, it is sufficient that the data is supplied within the time of 8 indices, which has a considerable time margin. Also, as for the molding time, the rotating arm returns to the gob delivery place, and the tray support rod may hold the gob tray with the heated gob, and then press it before reaching the gob delivery place. Also, the time margin of the press can be much longer than the conventional method. Therefore, depending on the properties of the glass, the length of the specified program,
Various types of pressing by instantaneous firing, slow running, or a combination thereof can be performed.

Further, even when it is necessary to produce a large number of lenses of the same type and type, mass production is possible if a large number of gob trays and press dies are made to be the same so as to fit the lenses. Further, by increasing the outflow of the glass from the melting tank, it is added to the efficiency, the productivity is increased by the increase in outflow as compared with the conventional apparatus, and the quality can be obtained much more easily than in the past. Also, even if the production situation needs to be reduced due to market conditions, it is not necessary to stop the entire device.The gob is formed with a small amount of outflow, and the post-process press device is partially stopped and put into operation. It is only necessary to be able to respond flexibly to the situation.
Others, such as “high-mix, low-volume production”, “high efficiency, low cost”, etc., are as described in the section on problem solving earlier.

[Brief description of the drawings]

FIG. 1 is a plan view showing the entire system of the present invention.

FIG. 2 is a front view schematically showing an example of a heating furnace.

FIG. 3 is a side view of an example of a press machine.

FIG. 4 is a plan view showing an example of a press unit including a material handling device, a heating furnace, and a press.

[Explanation of symbols]

1. Melting tank 2. Outflow pipe 3. Gob machine 4. Gob mold 5. Transfer device 6. Slide pad 7. First conveyor 8 _-1 to 8 _-8 . Heating furnace _9-1 to _9-8 . Press machine 10 _-1 to 10 _-8 . Extrusion mechanism 10 _-1a to 10 _-8a . V-shaped pusher 11 _{-1 to} 11 _-8 . Gob saucer 12 _{-1 to} 12 _-8 . XY stage 13 _{-1 to} 13 _-8 . Receiving tray support rod 14 _{-1 to} 14 _-8 . Rotary arm 15 _-1 to 15 _-8 . Press mold 16 _{-1 to} 16 _-8 . Material handling device 17. Heating furnace body 18. Heating furnace cover 19. Actuator 20. Opening 21. Grooves 22, 23. Insulation material 24 _-1 . Prop 24 _-2 . Guide bar 25. Upper mold 26. Lower type (26-1. Trunk type, 26-2. Arrow type) 27. Actuator 28. Actuator 29. Servo mechanism 30. Press machine body 31. Second conveyor 32. X slide 33. Y slide 34. Frame W. Gob P ₁ , P ₂ . In a press device showing a state in which a series of press units including a press product A to H, a heating furnace, a press machine, and a material handling device are arranged in parallel, A and B move a gob W to a gob tray 11 by an extruder 10. The XY stage 12 is operated and C and D indicate the receiving tray support rod 1.
3 shows a state in which the gob tray 11 supported by 3 is inserted into the heating furnace 8. E and F transfer heated gob W to gob tray 11
By moving the lid and the XY stage that are held by the XY stage, it moves to the place of delivery to and from the rotary arm 14, and shows a state in which the gob is being adsorbed. On the other hand, the XY stage has returned to the original position, the pushing device 10 has retreated, and is in a state of waiting for the next gob W to come. Q, R, and S indicate the change in the position of the X slide until the gob is heated by the heating furnace after being received, and further moved to the transfer position to the rotary arm and returned to the original position.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) C03B 9/00-17/06

Claims (6)

(57) [Claims] 1. A method for removing a gob from a molten glass, disposing several presses, and optionally providing a heating furnace, wherein the molten glass is directly received in a gob mold by a rotary index method. Equipped with a mechanism for forming the gob, a mechanism for taking out the gob from the gob mold and transferring it to a conveyor capable of keeping the temperature near the softening point of the glass as needed, and a mechanism for selectively distributing the gob to the gob tray. A single glass heating furnace that can be opened and closed by the instructions of the program and several single presses with a pair of upper and lower molds and a pressing device are provided in parallel, and further specified by each glass heating furnace. The gob is transferred to the forming press mold of the single press machine, and the pressed product is taken out from each press machine and transferred to the glass slow cooling mechanism on a conveyor. An apparatus for manufacturing an optical glass molded body, comprising a material handling apparatus to be transferred, and a series of these movements being controlled by program control by a relay or a computer system. 2. A gob of a predetermined size and weight is manufactured by arranging several types of gob molds for gob molding on a rotary table that can be rotated and divided, and according to the shape of the mold and the residence time accompanying the index of the rotary table. The manufacturing method according to claim 1, wherein the gob surface layer is moderately cooled to solidify the skin, taken out by a vacuum pad or another method, and transferred to a conveyor in the next step. 3. A transfer device having a mechanism for selectively distributing gobs to a preheating furnace, wherein the distributing mechanism is disposed at an outer edge from the center to the other end of the width of the upper surface of the conveyor made of a heat-resistant metal. The method according to claim 1, wherein the gob is pushed into the gob tray with a rod operated by an actuator when distributing the gob to the gob tray according to a pre-set program. 4. A gob kept in a predetermined high-temperature state is a single heating furnace for quickly reaching a high-temperature state suitable for press, and mainly presses the upper and lower molding dies during glass molding. 2. The manufacturing method according to claim 1, wherein the lower arrow, whose vertical position requires a delicate change, is controlled by a servo mechanism and an actuator controlled by a program assembled in advance. 5. In a press machine, the temperature of the upper and lower dies can be adjusted, and the moving gob has a reheating mechanism.
The manufacturing apparatus according to claim 1, further comprising a mechanism for directly reheating the upper surface of the lower mold with the combustion gas. 6. The gob tray is taken in and out of a heating furnace, the heated gob is transferred to a die of a press machine, and the pressed product after pressing is transferred to a second conveyor for transferring the pressed product to a glass slow cooling mechanism. The manufacturing apparatus according to claim 1, further comprising a changeable material handling mechanism.